Cytotoxic T lymphocyte antigen (CTLA)-4 plays an essential role in immunologic homeostasis. How this negative regulator of T cell activation executes its functions has remained controversial. We now provide evidence that CTLA-4 mediates a cell-intrinsic counterbalance to restrict the clonal expansion of proliferating CD4(+) T cells. The regulation of CTLA-4 expression and function ensures that,...

In the title compound, C(22)H(25)NO(4), the piperidine ring adopts a distorted boat conformation. The methyl groups at the 3 and 5 positions of the piperidine ring are in axial and equatorial orientations, respectively. Both H and O atoms in the aldehyde group are disordered over two positions with occupancies of 0.534 (5) and 0.466 (5). In the crystal, the mol-ecules are linked into a three-di...